git-submodule: forward exit code of git-submodule--helper more faithfully

git-submodule--helper is invoked as the upstream of a pipe in several
places. Usually, the failure of a program in this position is not
detected by the shell. For this reason, the code inserts a token in the
output stream when git-submodule--helper fails that is detected
downstream, where the shell script is quit with exit code 1.

There happens to be a bug in git-submodule--helper that leads to a
segmentation fault. The test suite triggers the crash in several places,
all of which are protected by 'test_must_fail'. But due to the inspecific
exit code 1, the crash remains undiagnosed.

Extend the failure protocol such that git-submodule--helper's exit code
is passed downstream (only in the case of failure). This enables the
downstream to use it as its own exit code, and 'test_must_fail' to
identify the segmentation fault as an unexpected failure.

The bug itself is fixed in the next commit.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Acked-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-submodule.sh b/git-submodule.sh
index 7c62b53..d876536 100755 (executable)
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -50,7 +50,7 @@ die_if_unmatched ()
 {
        if test "$1" = "#unmatched"
        then
-               exit 1
+               exit ${2:-1}
        fi
 }
 
@@ -312,11 +312,11 @@ cmd_foreach()
 
        {
                git submodule--helper list --prefix "$wt_prefix" ||
-               echo "#unmatched"
+               echo "#unmatched" $?
        } |
        while read mode sha1 stage sm_path
        do
-               die_if_unmatched "$mode"
+               die_if_unmatched "$mode" "$sha1"
                if test -e "$sm_path"/.git
                then
                        displaypath=$(git submodule--helper relative-path "$prefix$sm_path" "$wt_prefix")
@@ -423,11 +423,11 @@ cmd_deinit()
 
        {
                git submodule--helper list --prefix "$wt_prefix" "$@" ||
-               echo "#unmatched"
+               echo "#unmatched" $?
        } |
        while read mode sha1 stage sm_path
        do
-               die_if_unmatched "$mode"
+               die_if_unmatched "$mode" "$sha1"
                name=$(git submodule--helper name "$sm_path") || exit
 
                displaypath=$(git submodule--helper relative-path "$sm_path" "$wt_prefix")
@@ -580,12 +580,12 @@ cmd_update()
                ${depth:+--depth "$depth"} \
                ${recommend_shallow:+"$recommend_shallow"} \
                ${jobs:+$jobs} \
-               "$@" || echo "#unmatched"
+               "$@" || echo "#unmatched" $?
        } | {
        err=
        while read mode sha1 stage just_cloned sm_path
        do
-               die_if_unmatched "$mode"
+               die_if_unmatched "$mode" "$sha1"
 
                name=$(git submodule--helper name "$sm_path") || exit
                url=$(git config submodule."$name".url)
@@ -993,11 +993,11 @@ cmd_status()
 
        {
                git submodule--helper list --prefix "$wt_prefix" "$@" ||
-               echo "#unmatched"
+               echo "#unmatched" $?
        } |
        while read mode sha1 stage sm_path
        do
-               die_if_unmatched "$mode"
+               die_if_unmatched "$mode" "$sha1"
                name=$(git submodule--helper name "$sm_path") || exit
                url=$(git config submodule."$name".url)
                displaypath=$(git submodule--helper relative-path "$prefix$sm_path" "$wt_prefix")
@@ -1074,11 +1074,11 @@ cmd_sync()
        cd_to_toplevel
        {
                git submodule--helper list --prefix "$wt_prefix" "$@" ||
-               echo "#unmatched"
+               echo "#unmatched" $?
        } |
        while read mode sha1 stage sm_path
        do
-               die_if_unmatched "$mode"
+               die_if_unmatched "$mode" "$sha1"
                name=$(git submodule--helper name "$sm_path")
                url=$(git config -f .gitmodules --get submodule."$name".url)
 

diff --git a/t/t5815-submodule-protos.sh b/t/t5815-submodule-protos.sh
index 06f55a1..112cf40 100755 (executable)
--- a/t/t5815-submodule-protos.sh
+++ b/t/t5815-submodule-protos.sh
@@ -18,7 +18,7 @@ test_expect_success 'setup repository with submodules' '
        git commit -m "add submodules"
 '
 
-test_expect_success 'clone with recurse-submodules fails' '
+test_expect_failure 'clone with recurse-submodules fails' '
        test_must_fail git clone --recurse-submodules . dst
 '
 
@@ -32,7 +32,7 @@ test_expect_success 'update of ssh allowed' '
        git -C dst submodule update ssh-module
 '
 
-test_expect_success 'update of ext not allowed' '
+test_expect_failure 'update of ext not allowed' '
        test_must_fail git -C dst submodule update ext-module
 '
 

diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
index 3570f7b..fba2659 100755 (executable)
--- a/t/t7400-submodule-basic.sh
+++ b/t/t7400-submodule-basic.sh
@@ -352,7 +352,7 @@ test_expect_success 'sync should fail with unknown submodule' '
        test_failure_with_unknown_submodule sync
 '
 
-test_expect_success 'update should fail when path is used by a file' '
+test_expect_failure 'update should fail when path is used by a file' '
        echo hello >expect &&
 
        echo "hello" >init &&
@@ -361,7 +361,7 @@ test_expect_success 'update should fail when path is used by a file' '
        test_cmp expect init
 '
 
-test_expect_success 'update should fail when path is used by a nonempty directory' '
+test_expect_failure 'update should fail when path is used by a nonempty directory' '
        echo hello >expect &&
 
        rm -fr init &&